David House wrote:
I've added a bit more explanation, so it may now be palatable. It is quite a hard exercise, though, perhaps it shouldn't come so early on.
In my opinion, it is now much more clear. And it is a very instructive example. If people still find it too hard, you could add the additional hint: Keep in mind that there are no morphisms other than the ones shown in the diagram. Regards, Yitz _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe